The biggest problem this year has been the starting pitching depth. It is overlooked because they have three guys who have had good years in Burnes, Woodruff, and Laurer. Unfortunately 300+ starting pitching innings have been pitched by Ashby, Peralta, Houser, Gonzalez, Small, Alexander with a combined ERA near 5.
On the flip side, the offense hasn't really had any black holes in the lineup this year. No great hitters, but most nights it's a lineup of average hitters. Over the long run, that's been more successful than the boom or bust rotation.